Will a PCM from a 2003 TJ fit in my 2002?


toohak

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So I believe I found my issue is that my pcm is wrong. My tj is an 02 and the pcm was out of an '00, it physically plugged in but was getting no bus.

does anyone know if an 03 will work in my 02? Both jeep and pcm are non skim and I would only have to wait until tomorrow for this one rather than waiting on the mail.
 
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toohak

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I recently read here where someone installed a 2002 pcm into a 2003 so it seems possible it'd work going the other direction too.
I appreciate it. Unless someone tells me otherwise before in the morning I'm gonna try it. I hate to ask such basic questions here but this whole pcm situation is hard to get a straight answer from on Google
 

Wildman

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So I believe I found my issue is that my pcm is wrong. My tj is an 02 and the pcm was out of an '00, it physically plugged in but was getting no bus.

does anyone know if an 03 will work in my 02? Both jeep and pcm are non skim and I would only have to wait until tomorrow for this one rather than waiting on the mail.

I replied in your other thread and explained WHY the 2000 PCM won't work in your 2002 rig.
 
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Wildman

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Thank you, the person I originally bought everything for the swap off of gave me the '00 and I really didn't ever think of it, and when it physically plugged in I guess I assumed it was going to work.

Unless you are aware of the change from CCD to PCI in 2000 you wouldn't know any better. And yes they still use the same plugs and everything it's just the way the computer talks that is different.
 

Wildman

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@toohak It should start the car but I do not think the gauges will work. Let us know when you install it.

WOW this is good info. Why won't the gauges work?

It's like the 1997 Dodge Ram PCM will start a Jeep with a swapped in V-8 magnum engine but the gauges don't work. Curious to hear the reasons why.
 
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Wranglerfix

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There are a lot of J-Tech (1997-2004) Chrysler ECM’s that will work on more than one vehicle. A 1998 ECM can be made into a 97 or 98 but not the other way around unless there are letters after the 97.

After 1998, we use a variety of ECM’s to build depending on the year. I do not have the technical knowledge to explain the why’s and how’s but will find out on Monday for you.
 

JeepOnDecision

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There are a lot of J-Tech (1997-2004) Chrysler ECM’s that will work on more than one vehicle. A 1998 ECM can be made into a 97 or 98 but not the other way around unless there are letters after the 97.

After 1998, we use a variety of ECM’s to build depending on the year. I do not have the technical knowledge to explain the why’s and how’s but will find out on Monday for you.
@Wranglerfix have you ever considered creating a database of which year/model/option PCMs will fit which other year/model/options TJs? Would be very useful knowledge for trips to the salvage yard
 
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Wranglerfix

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@Wranglerfix have you ever considered creating a database of which year/model/option PCMs will fit which other year/model/options TJs? Would be very useful knowledge for trips to the salvage yard
I cannot do that because of trade secrets and doing business with wrecking yards.
 
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toohak

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Interestingly enough, all the guages work and the computer is recognized now. Just no start still unfortunately. It's raining too hard today to continue to mess with it but this is progress (I think)
My next steps are going to be having the starter tested and also getting a new key as I just noticed this one is horribly bent and I'm thinking this could be related.
 
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toohak

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As you can see, the guages are working again.

16332932653493518140974272339954.jpg
 
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Wildman

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Interestingly enough, all the guages work and the computer is recognized now. Just no start still unfortunately. It's raining too hard today to continue to mess with it but this is progress (I think)
My next steps are going to be having the starter tested and also getting a new key as I just noticed this one is horribly bent and I'm thinking this could be related.

I doubt the bent key has anything to do with it. I'd guess it's somewhere in your wiring. Something related to the Park/Neutral safety switch or the clutch inner-lock. If you can turn the key all the way to the start position I really don't think it's the key.
 

Wildman

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Here is something to try.

Put the transmission in neutral & set the parking brake & chock the tires so it can't roll/move.

Then do what this guy does in this video starting around the 3:40 point. Jump the lug on the starter solenoid and see if it cranks. If it does then it's your wiring.

 
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toohak

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Here is something to try.

Put the transmission in neutral & set the parking brake & chock the tires so it can't roll/move.

Then do what this guy does in this video starting around the 3:40 point. Jump the lug on the starter solenoid and see if it cranks. If it does then it's your wiring.

I'm gonna give this a go this evening, as the only code I'm getting now is p0443 which obviously wouldn't stop it from starting. My primary suspects at the moment are the starter (or starter wiring) or there's a possibility it's the ignition pin actuator as I used to have to be very rough with the key to get it to start and it may have finally broke completely.
 
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